ES2590577T3 - Method for isolating propane-1,3-diol from post-fermentation broth obtained by bioconversion - Google Patents

Abstract

A method for the isolation of propane-1,3-diol from the post-fermentation broth, which consists in the extraction of propane-1,3-diol by means of a mixture of organic solvents characterized in that propane is isolated. 1,3-diol, after the previous removal of biomass from the post-fermentation broth, with 2-butanone that is present in the organic solvent mixture in an amount of at least 10% or more.

Description

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DESCRIPTION

Method for isolating propane-1,3-diol from post-fermentation broth obtained by bioconversion

The present invention relates to a method of isolating propane-1,3-diol from post-fermentation broth by bioconversion.

Propan-1,3-diol is mainly used, in particular as a monomer, to generate polymeric PTT (poly (trimethylene terephthalate)) used in the production of fibers, carpets, textile materials, for medical and sanitary applications, and as a material for packaging and / or structural

As used herein, "bioconversion" is a synonym for any fermentation process that leads to an enzymatic / biochemical mode of propane-1,3-diol production.

US 7 056 439 B2 discloses a method of extracting propane-1,3-diol from fermentation broth with alcohols (pentanol, propanol, hexanol, oleyl alcohol), ketones (4-methyl-2-pentanone), esters (isopropyl acetate, tributyl phosphate), oleic acid, soybean oil, alkanes (n-hexane) and mixtures thereof. This method requires multiple extraction with different solvents and reverse extraction until aqueous phase. The maximum purity of isolated propane-1,3-diol is 95-98.5%.

US 5 008 473 discloses a method of isolating propane-1,3-diol with cyclohexane. This method is not appropriate for mixtures obtained in biotechnological processes and containing glycerol.

From EP 1 720 814 B1 a method is known for the isolation of hydrophilic organic compounds, including propane-1,3-diol, with glycol ether at a temperature and then as a result of heating at a higher temperature to obtain a higher temperature. aqueous extract with a hydrophilic and refined ether compound. The method is based on the extraction with ether glycols and a specific phenomenon to reduce the solubility of ether in the aqueous phase with increasing temperature. The method also discloses the addition of organic solvents in order to further decrease the solubility of glycol ethers in the aqueous phase during the reverse extraction stage to the aqueous phase. Among the additives, some ketones are mentioned in the memory. In this method, the organic solvent was not used only for extraction as such. This function is carried out by the glycol ether which, by nature, forces an increase in temperature and reverses the extraction to the aqueous phase. The complete solution, thus, constitutes the concentration of propane-1,3-diol in the aqueous phase, as in US 7 056 439 B2.

US 20100184783 discloses a process for the purification of particular diols, including propane-

1,3-diol, from the mixture of diols by extraction with an organic solvent or a mixture of organic solvents. An appropriate selection of the solvent mixture allows a selected diol group (comprising three, four and five carbon atoms) to be recovered, from the agitation mixture, in which the water content is at most 50% by weight . The method presented is not effective, however, for separating the diols from the post-fermentation broth with a glycerol content of less than 5% by weight, nor for the selective isolation of propane-1,3-diol. The method fails to complete the use of four-carbon ketones C-4 (2-butanone).

Document CN101012151A describes a method of isolating propane-1,3-diol from a post-fermentation broth containing trimethylene glycol within the range of (30-700 g / l) consisting of an initial saturation with inorganic salts (10-100%) and the addition of an organic solvent for extraction. The method refers to a specific fermentation broth with trimethylene glycol and comprises an expensive and technically inappropriate step of adding inorganic salt. The application of ketones with more than three carbons (C3) is omitted. CN 1907929 discloses a method of isolating propane-1,3-diol from a fermentation broth containing trimethylene glycol by means of extraction combined with chemical reaction. Propane-1,3-diol recovery is carried out for hydrolysis and distillation. This is an expensive and multistage process that reduces its effectiveness and has a negative impact on its profitability.

A similar recovery technique is presented by Malinowski et al. (Biotechnol. Prog. 16: 76-79, 2000). This extraction is based on the isolation of propane-1,3-diol by extraction with aldehydes, as reactants, converting propane-1,3-diol into an alkyl dioxane and the product is then extracted with organic solvents (toluene, or -xylene, ethylbenzene).

The process of extracting propane-1,3-diol from a post-fermentation broth with a mixture of ethyl acetate and ethanol is known in the art in Separation Science and Technology, 45: 541-547, 2010.

Propane-1,3-diol can also be recovered by continuous liquid-liquid extraction (Biotechnol. Tech., 13: 127-130, 1999). However, this process is presented as having limited efficacy due to its low ratio. of propane-1,3-diol distribution in organic solvents.

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Document CN 1460671 A discloses a stage of thermal concentration for the reduction of volume of the post-fermentation broth (which contains the product) and the stage of removal of biomass by means of precipitation with an organic solvent. Kquido-Kido extraction and mixing of the aqueous / organic phase are not mentioned. Mixing is carried out only during biomass washing after precipitation. Ethyl methyl ketone is added as a precipitating agent, only to remove the biomass, but not as an extracting agent. This is evidenced by the absence of phase distribution (aqueous / organic) and the extraction of the supernatant is not carried out.

The solution of document CN 1460671 A describes a process for the distillation of a mixture of water (from the post-fermentation broth) and an organic solvent (used for the precipitation of biomass). The solution described lacks the critical process of liquid-liquid extraction.

In the solution of the invention, the method has no concentration or precipitation steps and the organic solvent is used for liquid-liquid extraction and not for biomass precipitation.

In the present invention, unlike the solution of CN 1460671 A, the extracted substance (propane-

1,3-diol) in the liquid-liquid extraction is redistributed between a main solution (post-fermentation broth) and a secondary solution (organic solvent - ethyl methyl ketone, with which the key compound is extracted) . As a result, a refining is obtained (a solution that basically does not contain propane-1,3-diol) and an extract, which contains propane-1,3-diol. Only the extract (not the entire aqueous phase - the supernatant of steps 2 and 3 as in CN 1460671 A) is further purified (for example, subjected to distillation) to obtain a pure final product and a solvent ( extraction agent).

According to the invention, in the solvent recovery stage and the purification of the final product, due to effective counter-current extraction, the water content is minimized up to 12% of the water solubilized in the ethyl methyl ketone , due to the mixing during the liquid-liquid extraction process.

EP 0 261 554 A discloses the extraction of propane-1,3-diol with cyclohexane while the present invention relates to the isolation of propane-1,3-diol in continuous liquid-liquid extraction from a broth of post-fermentation (after removal of biomass) by means of 2-butanone and distillation of the final product.

EP 1103618B1 is based on a known method of ion exchange chromatography, in which propane-1,3-diol is isolated using a cationic resin and in the next stage an activated carbon column and a weak basic cationic resin or resin cationic and strong basic anionic resin. In this way, it differs from the invention in that propane-1,3-diol is isolated in the continuous liquid-liquid extraction from the post-fermentation broth (after the removal of biomass) by 2-butanone and distillation of final product .

US 6603048B1 discloses a method of isolating propane-1,3-diol from a post-fermentation broth, comprising propane-1,3-diol and other zeolites that cause fermentation as molecular sieves: products (between others, glycerol), which use molecular sieves, which are zeolites. The process is an example of the industrial use of a method of recovery of propane-1,3-diol from the post-fermentation broth. Despite its intended industrial use, the method uses a means of costly separation and separation of products on a semi-continuous basis that generates additional production and investment costs.

CN 10197556A discloses a super acid and solid catalyst method as a propane-1,3-diol isolation method followed by an aldol condensation reaction, and rectification.

The present invention relates to the continuous liquid-liquid extraction method from the post-fermentation broth (after the removal of biomass) with 2-butanone, without the use of a catalyst reaction and aldol reaction.

To date, there is no known continuous method for the extraction of propane-1,3-diol directly from the post-fermentation broth, obtained from almost any fermentation process to obtain propane-1,3-diol, by 2-butanone medium.

The inventors faced the need to obtain pure propane-1,3-diol and have developed a simple and inexpensive method for isolating propane-1,3-diol from a post-fermentation broth.

The object of the present invention is a method for the isolation of propane-1,3-diol from a post-fermentation broth consisting of the extraction of propane-1,3-diol by a mixture of organic solvents, characterized because propane-1,3-diol is isolated, after the previous removal of biomass from the post-fermentation broth, with 2-butanone that is present in the organic solvent mixture. The method is preferably carried out continuously or in stages and the organic solvent used in the extraction method is used repeatedly. The content of 2-butanone in the organic solvent mixture is at least 10%, and the volume ratio of post-fermentation broth, which contains propane-1,3-diol, with respect to the mixture of

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Organic solvents is at least 1: 3. After removal of previous biomass, the propane-1,3-diol isolation is carried out without the use of salt or concentration of the post-fermentation broth. The method of the invention is also characterized in that the isolation of propane-1,3-diol by means of the mixture of organic solvents is followed by vacuum distillation to obtain propane-1,3-diol of high purity. Preferably, the biomass is first removed from the post-fermentation broth comprising propane-1,3-diol, among others, by means of: ultrafiltration, filtration, centrifugation or sedimentation, and then propane extraction is carried out. -1,3-diol with a mixture of organic solvents.

The method of the invention for the recovery of propane-1,3-diol from the post-fermentation broth is based on the extraction of propane-1,3-diol continuously or in stages with an organic solvent, such as 2-butanone.

An advantage of the method of the invention is the high recovery ratio of propane-1,3-diol from the post-fermentation broth obtained by means of any fermentation process that leads to the production of propane-1,3-diol , as the main product. As a carbon source, glycerol or carbohydrates can be used.

The post-fermentation broth whose destiny is isolation may comprise glycerol residues, propane-1,3-diol, impurities such as organic acids, including mainly: acetic acid, butyric acid and carbohydrates (i.e., mainly glucose, fructose , dextrose, xylose, arabinose, water soluble starch fraction and cellulose residues). The presence of carbohydrates in the post-fermentation broth does not affect the effectiveness of the propane-1,3-diol extraction with 2-butanone.

The method guarantees the obtaining of a desired concentration of propane-1,3-diol in the extract with high efficiency, due to the possibility of recycling of the organic solvent used in the extraction process (either in a current line or in stages) . During the extraction of propane-1,3-diol from the post-fermentation broth, no emulsion is formed at the interface between the phases, which normally happens in the case of previously used solvents (ethyl acetate, n- hexane, toluene, 4-methyl-2-pentanone) and considerably restricts, if not impede, the use of said organic solvent in an industrial process.

The isolation is carried out directly from the post-fermentation broth without additional procedures, such as evaporation of water (concentration) or inorganic salt addition (as in the method of document CN101012151A). Only withdrawal from the post-fermentation broth is mandatory and no other operations are required (such as salt elimination). The propane-1,3-diol isolation method from the post-fermentation broth requires a low energy input. The extract obtained only is further distilled in vacuo to obtain a final product with a purity of 99.90%. The method is short (two stages), inexpensive and based on unique properties of an organic solvent never previously applied in said simple method. Due to the limitation of the number of isolation process stages and as a consequence, the costs of recovering propane-1,3-diol from the post-fermentation broth, the method of the invention is much more attractive than Other known methods.

The objective of the invention is presented in the following embodiments.

Example 1

After removal of biomass by centrifugation, the post-fermentation broth containing propane-1,3-diol (27.6 g / l, 100 ml) and 2-butanone (200 ml) was placed in the apparatus for continuous extraction (Soxhlet extractor for liquid-liquid extraction with an organic solvent lighter than water). 2-Butanone (150 ml) was heated in a round bottom flask for 1 h. Next, the propane-1,3-diol content in the organic and aqueous phases was determined. Continuous extraction of propane-1,3-diol was repeated 10 times for each new 100 ml portion of propane-1,3-diol post-fermentation mixture (27.6 g / l) with the same amount of solvent (without replacement). The average yield of the extraction process was 91%. The resulting post-fermentation mixture was subsequently distilled in vacuo and the final product, propane-1,3-diol, was obtained with a purity of 99.90%. Depending on the concrete pressure (9-18 mm Hg) the boiling point of propane-1,3-diol was varying within the range of 94-120 ° C.

Example 2

After removal of biomass by centrifugation, the post-fermentation broth containing propane-1,3-diol (35 g / l, 100 ml) and 2-butanone (200 ml) was placed in the apparatus for continuous extraction (extractor Soxhlet for liquid-liquid extraction with an organic solvent lighter than water). 2-Butanone (150 ml) was heated in a round bottom flask for 1 h. The propane-1,3-diol content in the organic and aqueous phases was determined. The continuous extraction of propane-1,3-diol was repeated 10 times for each new portion of 100 ml of propane-1,3-diol post-fermentation broth (35 g / l) with the same amount of solvent (without substitution). The average yield of the extraction process was 84%. The extract was subsequently distilled in vacuo and the final product, propane-1,3-diol, was obtained with a purity of 99.90%. Depending on the pressure (9-18 mm Hg) the boiling point of propane-1,3-diol was varying within the range of 94-120 ° C.

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Example 3

After removal of biomass by centrifugation, the post-fermentation broth containing propane-1,3-diol (60 g / l, 100 ml) and 2-butanone (200 ml) was placed in the continuous extraction apparatus (extractor Soxhlet for liquid-liquid extraction with an organic solvent lighter than water). 2-Butanone (150 ml) was heated in a round bottom flask for 1 h. The propane-1,3-diol content in the organic and aqueous phases was determined. The continuous extraction of propane-1,3-diol was repeated 10 times for each new portion of 100 ml of post-fermentation mixture of propane-1,3-diol (60 g / l) with the same amount of solvent (without substitution). The average yield of the extraction process was 73%. The extract was subsequently distilled in vacuo and the final product, propane-1,3-diol, was obtained with a purity of 99.90%.

Depending on the concrete pressure (9-18 mm Hg) the boiling point of propane-1,3-diol was varying within the range of 94-120 ° C.

Example 4

After removal of biomass by centrifugation, the post-fermentation broth containing propane-1,3-diol (35 g / l, 100 ml) and 2-butanone (200 ml) was placed in the apparatus for continuous extraction (extractor Soxhlet for liquid-liquid extraction with an organic solvent lighter than water). 2-Butanone (150 ml) was heated in a round bottom flask for 1.5 h. The propane-1,3-diol content in the organic and aqueous phases was determined. The continuous extraction of propane-1,3-diol was repeated 10 times for each new portion of 100 ml of post-fermentation mixture of propane-1,3-diol (35 g / l) with the same amount of solvent (without substitution). The average yield of the extraction process was 90%. The extract was subsequently distilled in vacuo and the final product, propane-1,3-diol, was obtained with a purity of 99.90%.

Depending on the concrete pressure (9-18 mm Hg) the boiling point of propane-1,3-diol was varying within the range of 94-120 ° C.

Example 5

After removal of biomass by centrifugation, the post-fermentation broth containing propane-1,3-diol (60 g / l, 100 ml) and 2-butanone (200 ml) was placed in the apparatus for continuous extraction (extractor Soxhlet for liquid-liquid extraction with an organic solvent lighter than water). 2-Butanone (150 ml) was heated in a round bottom flask for 2 h. The propane-1,3-diol content in the organic and aqueous phases was determined. Continuous extraction of propane-1,3-diol was repeated 10 times for each new portion of 700 ml of post-fermentation mixture of propane-1,3-diol (60 g / l) with the same amount of solvent (without substitution). The average yield of the extraction process was 92%. The extract was subsequently distilled in vacuo and the final product, propane-1,3-diol, was obtained with a purity of 99.90%.

Depending on the concrete pressure (9-18 mm Hg) the boiling point of propane-1,3-diol was varying within the range of 94-12 ° C.

Example 6

The results of the laboratory scale experiments were verified in the pilot scale test using extraction columns (Karr's vaiven column). After removal of biomass by centrifugation, the post-fermentation broth containing propane-1,3-diol (27 g / l) and 2-butanone were placed in separate containers and pumped at the ratio of 1: 7 (broth of post-fermentation comprising propane-1,3-diol: organic solvent, v / v) in the flow column of Karr in countercurrent flow. The column temperature range was 20-40 ° C. The process was carried out continuously. The average yield of the extraction process was 80%.

Example 7

After removal of biomass by centrifugation, the post-fermentation broth containing propane-1,3-diol (27 g / l) and 2-butanone were placed in separate containers and pumped at a ratio of 1: 10 (post-fermentation broth containing propane-1,3-diol: organic solvent, v / v) in a column of Karr flow in countercurrent flow. The temperature range of the column was 20-40 ° C. The process was carried out continuously. The average yield of the extraction process was 85%.

Example 8

After removal of biomass by centrifugation, the post-fermentation broth containing propane-1,3-diol (27 g / l) and 2-butanone were placed in separate containers and pumped at a ratio of 1: 15 (post-fermentation broth containing organic propane-1,3-diol solvent, v / v) in a column of Karr vaiven in

counter current flow. The temperature range of the column was 20-40 ° C. The process was carried out continuously. The average yield of the extraction process was 93%.

Example 9 5

After removal of biomass by centrifugation, the post-fermentation broth containing propane-1,3-diol (27 g / l) and 2-butanone were placed in separate containers and pumped at a ratio of 1: 7 (post-fermentation broth containing propane-1,3-diol: organic solvent, v / v) in a Scheibel extraction column in countercurrent flow. The temperature range of the column was 20-40 ° C. The process was carried out continuously. The average yield of the extraction process was 77%.

Example 10

After removal of biomass by centrifugation, the post-fermentation broth containing 15 propane-1,3-diol (27 g / l) and 2-butanone was placed in separate containers and pumped at a ratio of 1: 10 (post-fermentation broth containing propane-1,3-diol: organic solvent, v / v) in a Scheibel extraction column in countercurrent flow. The temperature range of the column was 20-40 ° C. The process was carried out continuously. The average yield of the extraction process was 88%.

20 Based on laboratory-scale experiments, it has been shown that the time of the process of extracting propane-1,3-diol with organic solvent should therefore be prolonged if the concentration of propane-

1,3-diol in the post-fermentation broth increases, to obtain a similar process efficiency using the same amount of organic solvent.

With pilot-scale experiments, the process is controlled by the volume ratio of post-fermentation broth (containing propane-1,3-diol) with respect to organic solvent.

Claims (7)

1. A method for isolating propane-1,3-diol from the post-fermentation broth, which consists in the extraction of propane-1,3-diol by means of a mixture of organic solvents characterized in that it is isolated 5 propane-1,3-diol, after the previous removal of biomass from the post-fermentation broth, with 2-butanone that is present in the organic solvent mixture in an amount of at least 10% or more. 2. The method according to claim 1, characterized in that said method is carried out continuously and the organic solvent used in the extraction method is used repeatedly. 10 3. The method according to claim 1, characterized in that said method is carried out in stages and the organic solvent used in the extraction process is used repeatedly. 4. The method according to any of claims 1-3, characterized in that the volume ratio of post-fermentation broth, which contains propane-1,3-diol, with respect to the organic solvent mixture is at least 1: 3. 5. The method according to any of claims 1-4, characterized in that after the previous removal of biomass, said propane-1,3-diol isolation is carried out without removal of salt or concentration of the 20 post-fermentation broth. 6. The method according to any of claims 1-5, characterized in that said propane-1,3-diol isolation by means of the organic solvent mixture is followed by vacuum distillation to obtain propane-1,3- high purity diol. 25 7. The method according to any of claims 1-6, characterized in that the biomass is first removed from the post-fermentation broth comprising propane-1,3-diol by means of one of the methods: ultrafiltration, filtration, centrifugation or sedimentation, and then the extraction of propane-1,3-diol is carried out with the mixture of organic solvents.